Method and apparatus for reading optical indicia using a plurality of data sources

ABSTRACT

A system for decoding an encoded symbol character associated with a product is provided. The system includes a scanning apparatus comprising a first scan source disposed within a housing, and a second scan source disposed within the housing. The second scan source comprises an operating technology distinct from an operating technology of the first scan source. The first scan source is adapted to output a first scan data set, and the second scan source is adapted to output a second scan data set. At least one of the first scan data set and the second scan data set comprises product bar code scan data.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. patent applicationSer. No. 13/359,087 for a Method and Apparatus for Reading OpticalIndicia Using a Plurality of Data Sources filed Jan. 26, 2012 (andpublished Aug. 2, 2012 as U.S. Patent Application Publication No.2012/0193416), now U.S. Pat. No. 8,678,286, which claims the benefit ofU.S. Patent Application No. 61/438,075 for a Method and Apparatus forReading Optical Indicia Using a Plurality of Data Sources filed Jan. 31,2011. Each of the foregoing patent applications, patent publication, andpatent is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

This disclosure relates generally to reading optical indicia and, morespecifically, to combining fragments of data from multiple sources todecode an optical indicia.

BACKGROUND

The use of optical indicia, or bar code symbols, for product and articleidentification is well known in the art. Presently, various types of barcode symbol scanners have been developed. One common type of bar codesymbol reader is the laser-based scanner, which uses a focused laserbeam to sequentially scan the bars and spaces of a bar code symbol to beread. The majority of laser scanners in use today, particular in retailenvironments, employ lenses and moving (e.g., rotating or oscillating)mirrors and/or other optical elements in order to focus and scan laserbeams across bar code symbols during code symbol reading operations.

In demanding retail scanning environments, it is common for such systemsto have both bottom and side-scanning windows to enable highlyaggressive scanner performance, so the cashier need only drag abar-coded product past these scanning windows for the bar code to beautomatically read with minimal assistance of the cashier or checkoutpersonal. Such dual scanning window systems are typically referred to as“bioptic” laser scanning systems as such systems employ two sets ofoptics—a first set disposed behind the bottom or horizontal scanningwindow, and a second set disposed behind the side-scanning or verticalwindow.

In general, prior art bioptic laser scanning systems are generally moreaggressive that conventional single scanning window systems. For thisreason, bioptic scanning systems are often deployed in demanding retailenvironments, such as supermarkets and high-volume department stores,where high check-out throughput is critical to achieving storeprofitability and customer satisfaction. While prior art biopticscanning systems represent a technological advance over most singlescanning window system, prior art bioptic scanning systems in generalsuffered from various shortcomings and drawbacks.

In particular, the laser scanning patterns of such prior art biopticlaser scanning systems are not optimized in terms of scanning coverageand performance, and the scanning systems are generally expensive tomanufacture by virtue of the large number of optical componentspresently required to construct such laser scanning systems.

Additionally, in scanning a bar code symbol and accurately producingdigital scan data signals representative of a scanned bar code symbol,the performance of such aggressive laser scanning systems is susceptibleto noise, including ambient noise, thermal noise and paper noise. Duringoperation of a laser scanning system, a focused light beam is producedfrom a light source such as a visible laser diode (VLD), and repeatedlyscanned across the elements of the code symbol. In the case of bar codescanning applications, the elements of the code symbol consists of aseries of bar and space elements of varying width. For discriminationpurposes, the bars and spaces have different light reflectivity (e.g.,the spaces are highly light-reflective while the bars are highlylight-absorptive). As the laser beam is scanned across the bar codeelements, the bar elements absorb a substantial portion of the laserbeam power, whereas the space elements reflect a substantial portion ofthe laser beam power. As a result of this scanning process, theintensity of the laser beam is modulated in accordance with theinformation structure encoded within the scanned bar code symbol.

As the laser beam is scanned across the bar code symbol, a portion ofthe reflected light beam is collected by optics within the scanner. Thecollected light signal is subsequently focused upon a photodetectorwithin the scanner which, in one example, generates an analog electricaloutput signal which can be decomposed into a number of signalcomponents, namely: a digital scan data signal having first and secondsignal levels, corresponding to the bars and spaces within the scannedcode symbol; ambient-light noise produced as a result of ambient lightcollected by the light collection optics of the system; thermal noiseproduced as a result of thermal activity within the signal detecting andprocessing circuitry; and “paper” or substrate noise, which may beproduced as a result of the microstructure of the substrate in relationto the cross-sectional dimensions of the focused laser scanning beam, ornoise related to the bar code printing quality (e.g., bar code edgeroughness, unwanted spots, void defects, and/or printing contrast).

The analog scan data signal has positive-going transitions andnegative-going transitions which signify transitions between bars andspaces in the scanned bar code symbol. However, a result of such noisecomponents or operating the scanner near the operational limits of thefocal zones, the transitions from the first signal level to the secondsignal level and vice versa are not perfectly sharp, or instantaneous.Consequently, it is sometimes difficult to determine the exact instantthat each binary signal level transition occurs in the detected analogscan data signal.

The ability of a scanner to accurately scan an encoded symbol characterand accurately produce digital scan data signals representative of ascanned bar code symbol in noisy environments depends on the depth ofmodulation of the laser scanning beam. The depth of modulation of thelaser scanning beam, in turn, depends on several important factors.Among the factors are (i) the ratio of the laser beam cross-sectionaldimensions at the scanning plane to the width of the minimal bar codeelement in the bar code symbol being scanned; (ii) the signal-to-noiseratio (SNR) in the scan data signal processor at the stage where binarylevel (1-bit) analog to digital (A/D) signal conversion occurs; (iii)the object distance; and (iv) the field of view (FOV) angle.

As a practical matter, it is not possible in most instances to produceanalog scan data signals with precisely-defined signal leveltransitions. Therefore, the analog scan data signal must be furtherprocessed to precisely determine the point at which the signal leveltransitions occur. Various circuits have been developed for carrying outsuch scan data signal processing operations. Typically, signalprocessing circuits capable of performing such operations includefilters for removing unwanted noise components, and signal thresholdingdevices for rejecting signal components which do not exceed apredetermined signal level. One drawback to these approaches is thatthermal and “paper” (or substrate) noise imparted to the analog scandata input signal tends to generate “false” positive-going andnegative-going transitions in the first derivative signal, and may alsogenerate zero-crossings in the second-derivative signal. Consequently,the circuit logic allows “false” first derivative peak signals andsecond-derivative zero-crossing signals to be passed on, therebyproducing erroneous binary signal levels at the output stage of thesignal processor. In turn, error-ridden digital data scan data signalsare transmitted to the digital scan data signal processor of the barcode scanner for conversion into digital words representative of thelength of the binary signal levels in the digital scan data signal. Thiscan result in significant errors during bar code symbol decodingoperations, causing objects to be incorrectly identified and/orerroneous data to be entered into a host system.

Another drawback to retail laser scanning systems is that the bar codelabel may be damaged or printed improperly. As is often the case, therebeing no redundancy in the scanning system, the bar code reader fails todecode and the cashier must input the bar code numbers manually, wastingvaluable time at the checkout counter and frustrating customers.

Yet another drawback to retail laser scanning systems is the opportunityfor theft by way of scanning the bar code of a significantly lessexpensive item instead of the item actually passing through thecheck-out line. Some retailers print their own bar codes to discountcertain items. The in-house bar codes are typically printed on stickersand set aside in a bin near the register. Cashiers or customers may peeloff these stickers and place them over an existing bar code for anexpensive item. As the expensive item is passed over the scan zone, thelaser scanner will recognize and decode the less expensive bar code as avalid item, and will complete the transaction at a loss for theretailer. In other fraudulent schemes, cashiers may place the in-housebar code sticker on their hand, and quickly scan their hand instead ofthe expensive item. Policing such fraudulent actions can betime-consuming and expensive. One method of policing that is presentlypracticed is to manually review the security camera video at the cashiercounter and cross-reference it with sales receipts to assure expensiveitems (as seen in the video) have been properly transacted. One drawbackto this approach is that the theft is identified long after the sale iscompleted and the customer has left the store.

SUMMARY

Accordingly, there is a need in the art for a retail laser scanner thatcan verify the authenticity of an item with its purported bar code labelat the time of checkout.

Moreover, there is a need in the art for an aggressive bioptic scannerthat overcomes the deficiencies with respect to laser scanner noise andlack of redundancy.

Even though bioptic laser scanners employ two sets of optics toaggressively scan and decode bar code symbols, the problems noted aboveapply equally to each of the horizontal and vertical laser systems.Thus, although the added complexity and cost of a bioptic laser scanningsystem may be beneficial in terms of aggressive scanning, the extralaser optics do not necessarily remedy the problems associated withreading the bar code (for example, noise).

In one aspect of the invention, a system for decoding an encoded symbolcharacter associated with a product is provided. The system includes abioptic scanning apparatus comprising a first scan source disposedwithin a housing, and a second scan source disposed within the housing.The second scan source comprises an operating technology distinct froman operating technology of the first scan source. The first scan sourceis adapted to output a first scan data set, and the second scan sourceis adapted to output a second scan data set. At least one of the firstscan data set and the second scan data set comprises product bar codescan data. The bioptic scanning apparatus further includes a centralprocessing unit adapted to execute a bar code decoding process bycross-referencing the first scan data set and the second scan data set.The system further includes a memory coupled to the central processingunit.

In another aspect of the invention, a method for decoding opticalindicia is provided. The method includes the step of providing a biopticscanning apparatus having a first scan source and a second scan source.The second scan source includes an operating technology distinct from anoperating technology of the first scan source. The method furtherincludes the steps of scanning with the first scan source an opticalindicia affixed to a product, and generating a first scan data set fromthe first scan source. The method further includes the steps of scanningthe product with the second scan source, and generating a second scandata set from the second scan source. The method further includes thesteps of combining the first scan data set with the second scan dataset, and decoding the optical indicia from the combined first scan dataset and second scan data set.

BRIEF DESCRIPTION OF THE DRAWINGS

The features described herein can be better understood with reference tothe drawings described below. The drawings are not necessarily to scale,emphasis instead generally being placed upon illustrating the principlesof the invention. In the drawings, like numerals are used to indicatelike parts throughout the various views.

FIG. 1 schematically illustrates an exemplary embodiment of a biopticbar code symbol scanning system in accordance with the presentinvention;

FIG. 2 is a block schematic diagram of a laser scanning system withinthe bioptic bar code symbol scanning system of FIG. 1; and

FIG. 3 is a block schematic diagram of an image scanning system withinthe bioptic bar code symbol scanning system of FIG. 1.

DETAILED DESCRIPTION

In the illustrative embodiments, the apparatus of the present inventionis realized in the form of an automatic bar code symbol scanning systemhaving a plurality of scan sources as well as a scan data processor fordecode processing scan data signals produced thereby. However, for thesake of convenience of expression, the term “bioptic scanner” shall beused hereinafter to denote the bar code symbol scanning system whichemploys the plurality of scan sources of the present invention.

FIG. 1 illustrates a point-of-sale workstation 10 used by retailers toprocess transactions involving the purchase of products bearing anencoded symbol character, typically a UPC symbol. The workstation 10includes a horizontal countertop 12 for placement of products to bescanned. A bioptic scanner 14 mounted within the countertop 12 includesa first housing portion 16 and a second housing portion 18 whichprojects from one end of the first housing portion in a substantiallyorthogonal manner. When the bioptic scanner 14 is installed within thecountertop surface, the first housing portion 16 is orientedhorizontally, whereas the second housing portion 18 is orientedvertically with respect to the point-of-sale (POS) station. Thus, asreferred to herein, the terms ‘first housing portion’ and‘horizontally-disposed housing portion’ may be used interchangeably butrefer to the same structure. Likewise, the terms ‘second housingportion’ and ‘vertically-disposed housing portion’ may be usedinterchangeably but refer to the same structure

The countertop 12 includes an optically transparent (e.g., glass)horizontal-scanning window 20 mounted flush with the checkout counter,covered by an imaging window protection plate 22 which is provided witha pattern of apertures 24 a. These apertures 24 permit the projection ofa plurality of vertical illumination planes from a first scan sourcelocated beneath the horizontal-scanning window 20, to be described morefully below.

The bioptic scanner 14 includes a vertical-scanning window 26 formed inthe second housing portion 18. The vertical-scanning window 26 furtherincludes a pattern of apertures 24 b to permit the projection of aplurality of horizontal illumination planes. The illumination may beprovided by the first scan source utilizing a series of splittingmirrors to direct some of the laser light from the source in thehorizontal portion through the vertical-scanning window 26 in the secondhousing portion 18. Alternately, a second scan source could provide theillumination, such as a separate laser scanner assembly.

A product 28 having an encoded symbol character 30 may be scanned by thebioptic scanner 14. If the encoded symbol character 30 is located on thebottom of the product 28, one of the scan lines projected through thehorizontal-scanning window 20 will traverse the symbol. If the character30 is located on the side of the product, then one of the scan linesprojected through the vertical-scanning window 26 will traverse thesymbol.

As used herein, “encoded symbol character” is intended to denote arepresentation of a unit of information in a message, such as therepresentation in a bar code symbology of a single alphanumericcharacter. One or more encoded symbol characters can be used to conveyinformation, such as the identification of the source and the model of aproduct, for example in a UPC bar code that comprises twelve encodedsymbol characters representing numerical digits. Also, an encoded symbolcharacter may be a non-alphanumeric character that has an agreed uponconventional meaning, such as the elements comprising bars and spacesthat are used to denote the start, the end, and the center of a UPC barcode. The bars and spaces used to encode a character as an encodedsymbol are referred to generally as “elements.” For example an encodedcharacter in a UPC symbol consists of four elements, two bars and twospaces. Similarly, encoded symbol characters can be defined for otherbar code symbologies, such as other one-dimensional (“1-D”) bar codesystems including Code 39 and Code 128, or for stacked two-dimensional(“2-D”) bar code systems including PDF417.

As used herein, bioptic scanner is not limited to a construction havinghorizontal and vertical scan windows. A bioptic scanner can include asingle scan window, such as the horizontal-scanning window illustratedin FIG. 1, but the scan window can have two (or more) scan sources.Although in some constructions the scan sources can be similar, inembodiments of the invention disclosed herein the scan sources comprisediffering technologies. For example, scan sources of differingtechnologies include a laser scanner, a radio frequency identificationdevice (RFID), a weight scale, or a multiple pixel image sensor array.The image array sensor may be distinguished by the operating softwareand include 1-D imagers, 2-D imagers, optical character recognitionreaders, pattern recognition devices, and color recognition devices, forexample.

In some constructions, the workstation 10 may further include a radiofrequency identification (RFID) reader 32; a credit card reader 34; awide-area wireless (WIFI) interface 36 including RF transceiver andantenna 38 for connecting to the TCP/IP layer of the Internet as well asone or more storing and processing relational database management system(RDBMS) server 40; a Bluetooth 2-way communication interface 42including RF transceivers and antenna 44 for connecting toBluetooth-enabled hand-held scanners, imagers, PDAs, portable computersand the like 46, for control, management, application and diagnosticpurposes. The workstation 10 may further include an electronic weightscale module 48 employing one or more load cells positioned centrallybelow the system's structurally rigid platform for bearing and measuringsubstantially all of the weight of objects positioned on thehorizontal-scanning window 20 or window protection plate 22, andgenerating electronic data representative of measured weight of suchobjects.

Referring to FIG. 2, a first scan source 50 located below thehorizontal-scanning window 20 comprises a laser scanner-based indiciareading terminal, or laser scanner 52. The laser scanner 52 includes alens assembly 54, which may include a fixed lens, a variable positionlens holder adapted for use with a movable lens system, or a variablefocus fluid lens, for example. The laser scanner 52 further includes alaser source 56 supported by the first housing portion 16. The lasersource 56 can emit a laser beam along an optical axis 58. Laser source56 can be coupled to laser source control circuit 60. Light from lasersource 56 can be shaped by collimating optics 62 and lens assembly 54.The combination of laser source 56 and collimating optics 62 can beregarded as a laser diode assembly 64. The laser beam travels in anemitting direction 66 along optical axis 58 and illuminates the product28, which in one embodiment includes the encoded symbol character 30. Ascanning mirror reflector 68 disposed within the optical path defined byaxis 58 oscillates to direct the laser beam across the entire surface tobe scanned. Reflector 68 can be driven by scan motor 70, M, which iscoupled to control circuit 72.

The laser beam reflects off the product 28 and travels along axis 58 ina receiving direction 74 back to a detector assembly 76. In the examplewherein the product 28 includes a bar code, the incident laser lightstrikes areas of dark and white bands and is reflected. The reflectedbeam will thusly have variable intensity representative of the bar codepattern. Detector assembly 76 including detector 78 and analog todigital converter 80 can receive the reflected beam of variableintensity, generate an analog signal corresponding to the reflectedbeam, and convert it to a digital data set for storage into first memory82 where it can be processed by CPU 84 in accordance with a programstored in non-volatile memory 86, provided in a particular example by anEPROM.

For attempting to decode a bar code symbol, CPU 84 can process adigitized image signal corresponding to a scanned, reflected, anddetected laser beam to determine a spatial pattern of dark cells andlight cells and can convert each light and dark cell pattern determinedinto a character of character string via table lookup. Laser scanner 52can include various interface circuits allowing CPU 84 to communicatewith various circuits of scanner 52 including first interface circuit 88coupled to laser source control circuit 60 and system bus 90, secondinterface circuit 92 coupled to motor control circuit 72, and thirdinterface circuit 94 coupled to electrical power input unit 96.

Referring to FIG. 3, there is shown a block diagram of a second scansource 98 disposed in the second housing portion 18 of the biopticscanner 14 (FIG. 1). The second scan source 98 comprises an operatingtechnology that is distinct from the operating technology of the firstscan source 50. That is, if the first scan source 50 is a laser scanner,the second scan source 98 will comprise an operating technology otherthan a laser scanner. In the illustrated embodiment, the second scansource 98 is a multiple pixel image sensor assembly 100, or opticalimager, such as a CCD scanner. In general, an image sensor arraysimultaneously illuminates all of the bars and spaces of a bar codesymbol with light of a specific wavelength in order to capture an imagefor recognition and decoding purposes. Such scanners are commonly knownas CCD scanners because they use CCD image detectors to detect images ofthe bar code symbols being read. As will be explained more fully below,FIG. 3 shows the basic structures that together comprise the generalform of an image sensor array that is suitable for use, and is genericto optical readers that use 1D image sensors and to optical readers thatuse 2D image sensors.

The image sensor assembly 100 can include an image sensor 102 comprisinga multiple pixel image sensor array 104 having pixels arranged in rowsand columns of pixels, column circuitry 106, and row circuitry 108.Associated with the image sensor 102 can be amplifier circuitry 110, andan analog-to-digital (A/D) converter 112 which converts imageinformation in the form of analog signals read out of multiple pixelimage sensor array 104 into image information in the form of digitalsignals. Image sensor 102 can also have an associated timing and controlcircuit 114 for use in controlling, e.g., the exposure period of imagesensor 102, and/or gain applied to the amplifier 110. The noted circuitcomponents 102, 110, 112, and 114 can be packaged into a common imagesensor integrated circuit 116. In one example, image sensor integratedcircuit 116 can be provided by an MT10V022 image sensor integratedcircuit available from Micron Technology, Inc. In another example, imagesensor integrated circuit 116 can incorporate a Bayer pattern filter. Insuch an embodiment, CPU 118 prior to subjecting a frame to furtherprocessing can interpolate pixel values intermediate of green pixelvalues for development of a monochrome frame of image data. In otherembodiments, red, and/or blue pixel values can be utilized for the imagedata.

In the course of operation of the image sensor assembly 100, imagesignals can be read out of image sensor 102, converted and stored into asystem memory such as RAM 120. A memory 122 of image sensor assembly 100can include RAM 120, a nonvolatile memory such as EPROM 124, and astorage memory device 126 such as may be provided by a flash memory or ahard drive memory. In one embodiment, image sensor assembly 100 caninclude CPU 118 which can be adapted to read out image data stored inmemory 122 and subject such image data to various image processingalgorithms. Image sensor assembly 100 can include a direct memory accessunit (DMA) 128 for routing image information read out from image sensor102 that has been subject to conversion to RAM 120. In anotherembodiment, image sensor assembly 100 can employ a system bus providingfor bus arbitration mechanism (e.g., a PCI bus) thus eliminating theneed for a central DMA controller. A skilled artisan would appreciatethat other embodiments of the system bus architecture and/or directmemory access components providing for efficient data transfer betweenthe image sensor 102 and RAM 120 are within the scope of the invention.

Referring to further aspects of image sensor assembly 100, the sensorassembly can include an imaging lens assembly 130 for focusing an imageof the encoded symbol character 30 onto image sensor 102. Imaging lightrays can be transmitted about an optical axis 132. Image sensor assembly100 can also include an illumination assembly 134 or excitationillumination module that comprises one or more of an illuminationpattern light source bank 136 for generating an illumination patternsubstantially corresponding to the field of view of image sensorassembly 100, and an aiming pattern light source bank 138 for generatingan aiming pattern. In use, the product 28 can be presented by anoperator to the image sensor assembly 100 in such manner that the aimingpattern is projected on the encoded symbol character 30. In the exampleof FIG. 3, the encoded symbol character 30 is provided by a 1D bar codesymbol. Encoded symbol characters could also be provided by 2D bar codesymbols or optical character recognition (OCR) characters.

The image sensor assembly 100 can further include a filter module 140that comprises one or more optical filters, as well as in someembodiments an actuator assembly 142 that is coupled generally to thefilter module, such as to the optical filters. The filter module 140 canbe located on either side of the imaging lens assembly 130. Likewise,one or more of the optical filters within the filter module 140 can bedisposed on one or more surfaces of the imaging lens assembly 130 and/orthe image sensor 102.

Each of illumination pattern light source bank 136 and aiming patternlight source bank 138 can include one or more light sources. Lensassembly 130 can be controlled with use of lens assembly control circuit144 and the illumination assembly 134 comprising illumination patternlight source bank 136 and aiming pattern light source bank 138 can becontrolled with use of illumination assembly control circuit 146. Filtermodule 140 can be controlled with use of a filter module control circuit148, which can be coupled to the actuator assembly 142. Lens assemblycontrol circuit 144 can send signals to lens assembly 130, e.g., forchanging a focal length and/or a best focus distance of lens assembly130. Illumination assembly control circuit 146 can send signals toillumination pattern light source bank 136, e.g., for changing a levelof illumination output.

Although not incorporated in the illustrated embodiments, image sensorassembly 100 can also include a number of peripheral devices such asdisplay 150 for displaying such information as image frames capturedwith use of image sensor assembly 100, keyboard 152, pointing device154, and trigger 156 which may be used to make active signals foractivating frame readout and/or certain decoding processes.

Image sensor assembly 100 can include various interface circuits forcoupling several of the peripheral devices to system address/data bus(system bus) bus 158, for communication with second CPU 118 also coupledto system bus 158. Image sensor assembly 100 can include interfacecircuit 160 for coupling image sensor timing and control circuit timingand control circuit 114 to system bus 158, interface circuit 162 forcoupling the lens assembly control circuit 144 to system bus 158,interface circuit 164 for coupling the illumination assembly controlcircuit 146 to system bus 158, interface circuit 166 for coupling thedisplay 150 to system bus 158, interface circuit 168 for couplingkeyboard 152, pointing device 154, and trigger 156 to system bus 158,and interface circuit 170 for coupling the filter module control circuit148 to system bus 158.

In a further aspect, image sensor assembly 100 can include one or moreI/O interfaces 172, 174 for providing communication with externaldevices (e.g., a cash register server, a store server, an inventoryfacility server, an image sensor assembly 100, a local area network basestation, a cellular base station). I/O interfaces 172, 174 can beinterfaces of any combination of known computer interfaces, e.g.,Ethernet (IEEE 802.3), USB, IEEE 802.11, Bluetooth, CDMA, and GSM.

In one embodiment, resources between the first scan source 50 and thesecond scan source 98 may be combined or shared to form a hybrid barcode symbol scanning system that improves the first-pass read rate andalso decreases misreads. For example, the system bus 90 of the firstscan source 50 may include or be the same as the bus 158 from the secondscan source 98. Further, the CPU 84 from the first scan source 50 mayinclude or be the same as the CPU 118 from the second scan source 98. Inthis manner, data sets obtained from processing the signals received byeach of the scan sources may be cross-referenced in order tosuccessfully decode a bar code. In one embodiment, one or both of theCPUs 84, 118 may execute a bar code decoding process bycross-referencing (or stitching) a first scan data set obtained from thefirst scan source 50 and a second scan data set obtained from the secondscan source 98.

In one example, the two optical sources 50, 98 are configured as a hostsystem and a slave system, with the host performing as the primaryoptical reader and the slave acting as a back-up. Both the host (e.g.,the laser scanner 52) and slave (e.g., the image sensor assembly 100)can capture the bar code passing through the scan zone. As describedabove, the host system can process the received signals and store afirst scan data set in first memory 82. Likewise, the slave system canprocess the received signals and store a second scan data set in secondmemory 122. Both the host laser scanner 52 and the slave image sensorassembly 100 can attempt to decode the encoded symbol character 30. Ifthe host system only obtains a partial read from the laser-basedreflection off the encoded symbol character 30, it may look foradditional data sets from other scan lines (e.g., multiple scan lines)and stitch them in a conventional manner. If conventional stitchingproves unsuccessful, the host system 52 may be configured to retrieveand combine the data sets obtained from the slave system 100 and stitchthem to the host data set according to a custom algorithm. For example,in a UPC bar code that comprises twelve encoded symbol charactersrepresenting numerical digits, the first scan source 50 may successfullydecode only seven of the characters. The second scan source 98 canprovide a data set comprising the remaining five characters, providingsufficient overlap exists to perform stitching.

This hybrid stitching methodology is especially advantageous when noise(e.g., ambient noise, thermal noise and paper noise) is prevalent in thelaser scanning system. The other operating technology will likely not bepredisposed to the same sources of noise, and therefore can increase thelikelihood of obtaining data sets that are decodable.

In another example, the scan source that decodes the encoded symbolcharacter 30 quickest will pass the result to the host system. In thismanner, the fastest possible decoding result is achieved, regardless ofthe host or slave system capabilities. For example, the slave opticalimager 98 may capture an image and post-process the bar code faster thanthe host laser scanner 50. The decoded result can be passed to the hostsystem, e.g., the laser scanner, as if the host had decoded the barcode. If, however, only a partial read is obtained by either system, thefirst and second scan data sets obtained may be stitched together by thecustom algorithm.

In some embodiments of the present invention, redundancy can be built into the retail transaction by programming one or more of the scan sources(or the point of sale system) to store a small database of patterns,color schemes, dimensions or other identifying marks for a specificnumber of bar codes. The bar codes may correspond to high-value SKUs,for example, or any and all of the products offered for sale in theretail establishment. In this manner, the added security of matchingcolor or image can be utilized to prevent theft. Alternatively, the barcodes can be known codes that are difficult to scan, so reducing manualkey-ins would improve productivity.

Thus, the second scan source 98 need not comprise a bar code reader. Inanother embodiment of the invention, the second scan source 98 is animage sensor array such as a digital camera. The digital camera capturesan image of the item 28 being scanned and stores it as a second scandata set, for example in RAM 120. The CPU 118 can be adapted to comparethe image of the product 28 with pre-stored patterns or imagescorresponding to the bar code being scanned. If the pre-stored imagesmatch the image of the product 28, the sale of the item is completed.The image or pattern comparison can assure the expected pattern/color islocated at the correct distance/orientation from the bar code, forexample. In another example, dimensions of the product being scannedcould be cross-referenced with a database storing the actual dimensionsassociated with the particular bar code. Referring briefly to FIGS. 1and 3, the dimensions “a,” “b,”, and “c” of product 28 can be associatedwith encoded symbol character 30 in memory 122. If the bar code 30 beingscanned corresponds to a small, inexpensive item stored in RDBMS server40 for example, but the image capture reveals the actual dimensions(e.g., a, b, c) of product 28 to be a large, expensive item, thetransaction can be stopped. Thus, if the images or patterns do notmatch, a warning can be initiated alerting the cashier or even securitypersonnel. In this manner, retail theft of expensive items can bereduced if a customer or cashier attempts to pass off a fake bar code.

In another embodiment of the invention, the second scan source 98comprises an imaging scan module with a color sensor adapted to capturecolor patterns within the bar code. In one example, the color of the barcode can be captured as the second scan data set and cross-referenced toa stored value to provide redundancy in the retail environment. In muchthe same way, the color surrounding the perimeter of the bar code can becaptured as the second scan data set and cross-referenced to a storedvalue. In the color matching example, one possible implementationrequires that a significant portion of the bar code be identified by thestitching methodologies disclosed herein, then that data set could becompared to a database which would then have the scanner validate that,given the complete data string (or large enough portion), the expectedcolor is located at the correct distance or orientation from the barcode.

In another embodiment of the invention, the second scan source 98comprises an imaging scan module adapted to capture alphanumericcharacters. The image (second scan data set) obtained by the second scansource 98 can be post-processed and, utilizing optical characterrecognition (OCR) software stored in memory EPROM 124 for example, thealphanumeric characters of the bar code can be identified. In thismanner, any characters indiscernible by the first scan source 50 may becross-referenced or stitched from the second scan source 98.

In yet another embodiment of the invention, the second scan source 98comprises the RFID reader 32 for redundancy. Thus, an imager is notrequired to generate a second scan data set for cross-referencing. Inone example, the RFID reader 32 can be integrated into in the laserscanner 52. An RFID tag can be read on a product 28, and the RFID readercan obtain the electronic product code (EPC) as the second scan data setand convert that to an actual bar code for lookup. If the product 28having an RFID tag also has a bar code on it, the bar code scanner(first scan source 50) will read that bar code 30 and also have thatdata set available to be cross-referenced with the bar code generated bythe RFID reader 32. In this manner, a measure of redundancy is added inthe event the first scan source 50 cannot obtain a good read.

In yet another embodiment of the invention, the first scan source 50 isthe weight scale module 48 and the second scan source 98 is a multiplepixel image sensor assembly 100. The image sensor assembly 100 canperform a multiplicity of operations, depending upon the software loadedtherein, such as decoding the bar code 30, pattern matching, or colormatching. In one example, the image sensor assembly 100 can performdecoding operations on the bar code 30 and, once the product 28 isidentified, the measured weight of the product can be compared to theweight of the item stored in a memory location, such as storage memorydevice 126 or RDBMS server 40.

The above-described invention is not limited to two scan sources. Asmany differing-technology scan sources as practical may be utilized toachieve the desired redundancy or aggressive processing speed. Inanother embodiment, three scan sources are utilized comprising a laserscanner, a multiple pixel image sensor, and OCR. In one example, a firstscan data set comprises four characters of a UPC bar code obtained fromthe laser scanner. A second scan data set obtained from the imagercomprises seven characters of the bar code, and third data set comprisesfive characters of the bar code obtained from OCR software. Usingstitching techniques, the three data sets can be compared and overlapsidentified in order to acquire the twelve-character UPC code. In anotherexample, three complete data sets are cross-referenced for redundancy.In the event all three date sets do not match exactly, algorithms may beused to choose which characters belong to the code (for example, two outof three matching).

One of the improvements of the present disclosure is that the first-passread rate is increased. By utilizing custom stitching techniques frommultiple data sets obtained from scan sources of differing technologies,partial bits of information can be combined in hybrid fashion to obtaina good read on the first pass, rather having a decode error andresorting to manual input.

Further, retail theft can be reduced because a scanned bar code can becross-referenced to other identifying information to assure the bar codematches the correct product.

A system for decoding an encoded symbol character associated with aproduct is provided. The system includes a bioptic scanning apparatuscomprising a first scan source disposed within a housing, and a secondscan source disposed within the housing. The second scan sourcecomprises an operating technology distinct from an operating technologyof the first scan source. The first scan source is adapted to output afirst scan data set, and the second scan source is adapted to output asecond scan data set. At least one of the first scan data set and thesecond scan data set comprises product bar code scan data. The biopticscanning apparatus further includes a central processing unit adapted toexecute a bar code decoding process by cross-referencing the first scandata set and the second scan data set. The system further includes amemory coupled to the central processing unit. In one embodiment, thefirst scan source is a laser scanner, and the second scan source is amultiple pixel image sensor assembly. In one example, the multiple pixelimage sensor assembly is adapted to capture an image of the encodedsymbol character, the second scan data set comprises bar code data, andthe central processing unit is adapted to execute a bar code decodingprocess by stitching the first scan data set and the second scan dataset.

While the present invention has been described with reference to anumber of specific embodiments, it will be understood that the truespirit and scope of the invention should be determined only with respectto claims that can be supported by the present specification. Further,while in numerous cases herein wherein systems and apparatuses andmethods are described as having a certain number of elements it will beunderstood that such systems, apparatuses and methods can be practicedwith fewer than the mentioned certain number of elements. Also, while anumber of particular embodiments have been described, it will beunderstood that features and aspects that have been described withreference to each particular embodiment can be used with each remainingparticularly described embodiment.

A sample of systems and methods that are described herein follows:

A1. A system for decoding an encoded symbol character associated with aproduct, the system comprising:

a bioptic scanning apparatus comprising a first scan source disposedwithin a housing; a second scan source disposed within the housing, thesecond scan source comprising an operating technology distinct from anoperating technology of the first scan source; the first scan sourceadapted to output a first scan data set; the second scan source adaptedto output a second scan data set; and further comprising a centralprocessing unit adapted to execute a bar code decoding process bycross-referencing the first scan data set and the second scan data set;

a memory coupled to the central processing unit;

wherein at least one of the first scan data set and the second scan dataset comprise product bar code scan data.

A2. The system of A1 wherein the first scan source is a laser scanner,the second scan source is a multiple pixel image sensor assembly, andthe first scan data set comprises bar code data.

A3. The system of A2 wherein the multiple pixel image sensor assembly isadapted to capture an image of the encoded symbol character, the secondscan data set comprises bar code data, and the central processing unitis adapted to execute a bar code decoding process by stitching the firstscan data set and the second scan data set.

A4. The system of A1 wherein the first scan data set comprises productbar code scan data, the second scan source comprises a multiple pixelimage sensor assembly adapted to capture an image of alphanumericcharacters associated with the product bar code, the second scan dataset comprises alphanumeric characters associated with the product barcode, and the central processing unit is adapted to access opticalcharacter recognition software to compare the product bar code scan datawith the alphanumeric characters.

A5. The system of A4, wherein the first scan source is a laser scanner.

A6. The system of A1, wherein the first scan data set comprises productbar code scan data and the second scan source comprises a radiofrequency identification reader.

A7. The system of A6, wherein the second scan data set comprises barcode data associated with the first scan data set stored in the memoryof the system, the second scan data set obtained from associating anelectronic product code output by the radio frequency identificationreader.

A8. The system of A1 wherein the first scan data set comprises productbar code scan data and the second scan source comprises a multiple pixelimage sensor assembly adapted to capture and output as the second scandata set color images associated with the product, the centralprocessing unit adapted to compare the color images output from themultiple pixel image sensor assembly with product color imagesassociated with the first scan data set stored in the memory of thesystem.

A9. The system of A1 wherein the first scan data set comprises productbar code scan data and the second scan source comprises a multiple pixelimage sensor assembly adapted to capture and output as the second scandata set pattern images associated with the product, the centralprocessing unit adapted to compare the pattern images output from themultiple pixel image sensor assembly with product pattern imagesassociated with the first scan data set stored in the memory of thesystem.

A10. The system of A1 wherein the first scan data set comprises productbar code scan data and the second scan source comprises a weight scalemodule adapted to output as the second scan data set a weight associatedwith the product, the central processing unit adapted to compare theweight of the product with product weights associated with the firstscan data set stored in the memory of the system.

A11. The system of A1 wherein the housing comprises a horizontal sectionintegrally connected to a vertical section, the horizontal sectioncomprising a horizontal-scanning window formed therein, the first scansource aligned with the horizontal-scanning window, the vertical sectioncomprising a vertical-scanning window substantially orthogonal to thehorizontal-scanning window, the second scan source aligned with thevertical-scanning window.

B1. A method for decoding optical indicia, comprising the steps of:

providing a bioptic scanning apparatus having a first scan source and asecond scan source, the second scan source comprising an operatingtechnology distinct from an operating technology of the first scansource;

scanning with the first scan source an optical indicia affixed to aproduct;

generating a first scan data set from the first scan source;

scanning the product with the second scan source;

generating a second scan data set from the second scan source;

cross-referencing the first scan data set with the second scan data set;and

decoding the optical indicia from the cross-referenced first scan dataset and second scan data set.

B2. The method of B1, wherein the step of scanning the product with thesecond scan source comprises scanning the optical indicia on theproduct.

B3. The method of B2, wherein the first scan source is a laser scannerand the second scan source is a multiple pixel image sensor assembly.

B4. The method of B2, wherein the step of combining the first scan dataset with the second scan data set comprises combining a portion of thefirst scan data set with a portion of the second scan data set.

B5. The method of B4, wherein the combining step is stitching.

B6. The method of B1, wherein the step of combining the first scan dataset with the second scan data set comprises cross-referencing the secondscan data set with the first scan data set for redundancy.

B7. The method of B1, wherein the step of scanning the product with thesecond scan source comprises generating an image of the product.

B8. The method of B7, wherein the step of combining the first scan dataset with the second scan data set comprises comparing the second scandata set with pre-stored product features associated with the first scandata set.

B9. The method of B8, wherein the pre-stored product features aredimensions.

B10. The method of B8, wherein the pre-stored product features arecolors.

B11. The method of B8, wherein the pre-stored product features arepatterns.

B12. The method of B1, wherein the step of scanning the product with thesecond scan source comprises scanning the product with a radio frequencyidentification reader.

B13. The method of B12, wherein the radio frequency identificationreader obtains an electronic product code of the product, converts theelectronic product code to a bar code as the second scan data source,and compares to the bar code to the first scan data set.

B14. The method of B1, wherein the step of decoding the optical indiciafrom the combined first scan data set and second scan data set comprisesdetermining which scan data set decoded the optical indicia quickest.

1. A system comprising: memory for storing data; a laser scanner foroutputting a first data set comprising barcode data; an image sensor foroutputting a second data set comprising barcode data; and a centralprocessing unit for executing a decoding process by combining the firstdata set and the second data set.
 2. The system of claim 1, wherein thedecoding process executed by the central processing unit comprisesstitching the first data set and the second data set.
 3. The system ofclaim 1, wherein: the first data set comprises barcode data from aproduct barcode; the second data set comprises alphanumeric charactersassociated with the product barcode; and the central processing unit isconfigured for executing optical character recognition software and forcomparing the barcode data from the product barcode with thealphanumeric characters associated with the product barcode.
 4. Thesystem of claim 1, comprising a radio frequency identification readerfor outputting a third data set.
 5. The system of claim 4, wherein: thethird data set comprises an electronic product code; and the centralprocessing unit is configured for executing a decoding process bycombining the first data set, the second data set, and the third dataset.
 6. The system of claim 1, wherein: the first data set comprisesbarcode data from a product; the second data set comprises color imagesassociated with the product; and the central processing unit isconfigured for comparing the barcode data from the product with thecolor images associated with the product.
 7. The system of claim 1,wherein: the first data set comprises barcode data from a product; thesecond data set comprises pattern images associated with the product;and the central processing unit is configured for comparing the barcodedata from the product with the pattern images associated with theproduct.
 8. The system of claim 1, comprising a weight scale module foroutputting a third data set comprising a weight associated with theproduct, wherein the central processing unit is configured for comparingthe third data set with product weights associated with the first scandata set in the memory.
 9. A system comprising: a laser scanner foroutputting a first data set; an image sensor for outputting a seconddata set; and a central processing unit for executing a decoding processby combining the first data set and the second data set.
 10. The systemof claim 9, wherein the decoding process executed by the centralprocessing unit comprises stitching the first data set and the seconddata set.
 11. The system of claim 9, wherein: the first data setcomprises barcode data from a product barcode; the second data setcomprises alphanumeric characters associated with the product barcode;and the central processing unit is configured for executing opticalcharacter recognition software and for comparing the barcode data fromthe product barcode with the alphanumeric characters associated with theproduct barcode.
 12. The system of claim 9, comprising a radio frequencyidentification reader for outputting a third data set.
 13. The system ofclaim 12, wherein: the third data set comprises an electronic productcode; and the central processing unit is configured for executing adecoding process by combining the first data set, the second data set,and the third data set.
 14. The system of claim 9, wherein: the firstdata set comprises barcode data from a product; the second data setcomprises color images associated with the product; and the centralprocessing unit is configured for comparing the barcode data from theproduct with the color images associated with the product.
 15. Thesystem of claim 9, wherein: the first data set comprises barcode datafrom a product; the second data set comprises pattern images associatedwith the product; and the central processing unit is configured forcomparing the barcode data from the product with the pattern imagesassociated with the product.
 16. The system of claim 9, comprising aweight scale module for outputting a third data set comprising a weightassociated with the product, wherein the central processing unit isconfigured for comparing the third data set with product weightsassociated with the first scan data set in a memory.
 17. A systemcomprising: a laser scanner for outputting a first data set; an imagesensor for outputting a second data set; and a central processing unitfor executing a decoding process comprising stitching the first data setand the second data set.
 18. The system of claim 17, wherein: the firstdata set comprises barcode data from a product barcode; the second dataset comprises alphanumeric characters associated with the productbarcode; and the central processing unit is configured for executingoptical character recognition software and for comparing the barcodedata from the product barcode with the alphanumeric charactersassociated with the product barcode.
 19. The system of claim 17,comprising a radio frequency identification reader for outputting athird data set.
 20. The system of claim 19, wherein: the third data setcomprises an electronic product code; and the central processing unit isconfigured for executing a decoding process by combining the first dataset, the second data set, and the third data set.
 21. The system ofclaim 17, wherein: the first data set comprises barcode data from aproduct; the second data set comprises color images associated with theproduct; and the central processing unit is configured for comparing thebarcode data from the product with the color images associated with theproduct.
 22. The system of claim 17, wherein: the first data setcomprises barcode data from a product; the second data set comprisespattern images associated with the product; and the central processingunit is configured for comparing the barcode data from the product withthe pattern images associated with the product.
 23. The system of claim17, comprising a weight scale module for outputting a third data setcomprising a weight associated with the product, wherein the centralprocessing unit is configured for comparing the third data set withproduct weights associated with the first scan data set in a memory.